IMPROVEMENT IN PRODUCTION OF SINGLE- AND MULTI-LAYER THERMOPLASTIC FOILS

摘要

A process and an apparatus for the production of a flat mono- or multi-layer thermoplastic film (2) for packaging, comprising a flat extrusion die (1) and a chill roll (6) provided with an internal cooling system. A liquid knife device (10) is associated with said chill roll (6) for spouting a continuous and substantially uniform liquid knife (20) at a predetermined speed and temperature, said liquid knife device (10) being provided with a slot (19) which has an adjustable outflow cross section (21) and is fed with a liquid at a predetermined temperature and flow rate.